Part 131

=Colors=, different in birds’ eggs, 233 in sunset, cause of, 253

=Color=, of rainbow, 253 red, why it makes a bull angry, 490

=Columbus=, brought first sheep to America, 80

=Comb honey=, development of (illus.), 529

=Compounds=, compared with elements, 349

=Compressed air=, method in building tunnels, 211

=Concrete=, buildings (illus.), 100 construction (illus.), 100 decay, 101 engineering, 102 forms (illus.), 100 houses (illus.), 101 loads (illus.), 100 mold, 101 ornamental (illus.), 100 practical uses of (illus.), 100 rusting, 100 Silo (illus.), 102 stable (illus.), 102 sun dial (illus.), 101 tensile strain, 104 tower (illus.), 102 walls (illus.), 100 water tower (illus.), 102 what it is, 95 wood, 102

=Confucius=, philosophy written with brush, 13

=Cooking=, when first used, 308

=Copper=, as a conductor of electricity, 267 wire, telegraph, 266

=Corn plant=, how pollen fertilizes, 170 why it has silk, 176

=Corn Silk=, what it is for, 176 baling presses (illus.), 476

=Cotton=, drawing frames (illus.), 472 slashers (illus.), 475 spinning frames (illus.), 473 warping machine (illus.), 474 what nation produces the most, 477 how much cloth will a pound of cotton make, 477 mill (illus.), 471 cloth, first steps in making, 472 putting fiber on bobbins (illus.), 473 cloth finished (illus.), 476 who discovered, 477 weave room, 475 where it comes from, 470 lapper machines, 471 card room (illus.), 472 bobbins (illus.), 473 dye-house (illus.), 474 beaming frames (illus.), 475 inspecting tables (illus.), 476 field a southern (illus.), 470 breaker machines (illus.), 471 slubber machines (illus.), 472 speeders (illus.), 473 spooling machine (illus.), 474 shipping (illus.), 476 what used for, 477 cloths, what are the principle, 477

=Counting=, man, himself, 19 in tens, 19 in twelves, 20

=Crying=, what makes us, 195 when hurt, why we, 93

=Cross-bow=, invention of, 44

=Crude rubber=, how treated, 378

=Culverins=, early type of, 45

=Cylinder in gas engine= (illus.), 184

=Darkness=, cats can see in, 91 some animals can see in, 91 why we cannot see in, 91 why we fear, 352

=Deep sea diving=, the telephone adjusting (illus.), 202 coming up (illus.), 204 cost of outfit, 203 helmet, putting on (illus.), 202 just before going down (illus.), 204 outfit, 202 shoes, putting on (illus.), 202 suit, putting on (illus.), 202 telephoning from bottom, 203 telephone, testing the (illus.), 203 testing, final (illus.), 203 water pressure at varying depths, 203 wealth recovered by diving, 204 weight of outfit, 203

=Deer-stalking with the cross-bow= (illus.), 42

=Detonators=, in firearms, 47

=Developer=, Pyro, in photography, 23

=Diamonds=, what made of, 351

=Did= candles come before lamps? 294

=Die=, why do we have to, 245

=Difference= in woolens and worsteds, 84